The old upper town residents? (6,8)

I believe the answer is:

senior citizens

I'm a little stuck... Click here to teach me more about this clue!

'the old upper town residents?' is the definition.
The definition and answer can be both people as well as being plural nouns.
Maybe they are linked in a way I don't understand?

'old upper town residents?' is the wordplay.
'old' becomes 'senior' (associated in meaning).
'upper town residents?' becomes 'citizens' (I am not sure about this - if you are sure you should believe this answer much more).
'senior'+'citizens'='SENIOR CITIZENS'

Can you help me to learn more?

I've seen this clue in The Telegraph.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.